Section 5 The Cell Cycle

The Cell Cycle Humans go through stages of life. Babies, children, teenagers, and adults are all at different stages. Cells go through stages too. When cells go through stages of life, it is called the cell cycle.

The Cell Cycle The cell cycle is the process cells go through to: GrowGrow Copy their DNACopy their DNA Divide to make new cellsDivide to make new cells The cell cycle starts when a cell is formed and ends when the cell divides to make new cells.

The Cell Cycle Different types of cells divide in different ways. Before any cell divides, it makes a copy of its DNA. Remember, DNA is a molecule that determines what cells will do.

The Cell Cycle A cell copies its DNA so that each new cell will have the code that is needed to make new proteins and survive.

The Cell Cycle Cells make new cells in two different ways, depending on what type of cells they are: 1.B inary Fission 2. Mitosis

BINARY FISSION Simple organisms have a simple method for making new cells. Prokaryotes are cells that do not have a nucleus. Bacteria cells are prokaryotes. Prokaryotes reproduce through binary fission.

BINARY FISSION After a prokaryote copies its DNA, it splits into two parts and becomes two cells. Each cell has a copy of the DNA.

BINARY FISSION After the cell splits, each new cell is exactly the same as the cell that it came from.

Eukaryotic Cell Division Eukaryotes are cells that have a nucleus. Animal cells are eukaryotes.

Eukaryotic Cell Division Before this type of cell divides, it copies its DNA. It does this by copying its chromosomes.

Eukaryotic Cell Division Chromosomes are tiny packets of DNA inside a eukaryote's nucleus.

Eukaryotic Cell Division Once the chromosomes are copied, the cell goes through the second phase of its cell cycle, called MITOSIS.

Eukaryotic Cell Division MITOSIS is the separation of chromosomes. After the cell goes through mitosis, the cell divides and makes two new cells.

THE STAGES OF MITOSIS There are four stages of mitosis: 1.Prophase 2.Metaphase 3.Anaphase 4.Telophase

PROPHASE PROPHASE: 1.The chromosomes thicken and shrink into rod-like structures. 2.The nuclear membrane dissolves.

METAPHASE METAPHASE: 1.The chromosomes line up along the midline of the cell.

ANAPHASE ANAPHASE: 1.The chromosomes separate and move to opposite sides of the cell.

TELOPHASE TELOPHASE: 1.The chromosomes start to grow back to their original size. 2.The nuclear membrane reforms. 3.The cytoplasm of the mother cell divides and forms two daughter cells.

TELOPHASE TWO NEW CELLS: Each daughter cell has the same number and type of chromosomes as the mother cell.

MITOSIS